It is believed that all unrecorded videotape cassettes now on the market (including both "VHS" and "Betamax") have a breakout record tab which permits one to record on the tape until the tab is broken out. After the tab is broken out, a record-lockout finger on the recorder can enter the opening that the breakout tab had blocked. Such movement of the finger disables the record mechanism. When one later wishes to erase or make a new recording, the usual procedure is to cover the record-lockout opening with a piece of tape to prevent the record-lockout finger from entering the opening and disabling the record mechanism. If tape is not immediately available, the user might plug the opening with an object that could damage either the recorder or the tape. A piece of tape not only is unsightly, but its application and subsequent removal might result in a sticky deposit which could attract dirt and might cause the videotape and record mechanism to become contaminated.
Because of such problems, a variety of suggestions have been offered that would eliminate the need for tape to close an open record-lockout opening. Most, if not all, such suggestions concern record tabs which either are removably inserted into a record-lockout opening or are permanently positioned within such an opening and can be moved either to block or unblock the opening. In U.S. Pat. No. 4,012,011 (Saito), a number of such tabs or lugs are described, "and the information which is obtained by detecting the presence or absence or the disposition of the lug can be utilized for the purpose of preventing an inadvertent erasure as well as distinguishing between a stereophonic and an educational tape, switching of a tape speed, a selection of Dolby circuit and switching of a bias voltage, or any combination thereof" (col. 12, lines 13-20). Even though the Saito patent specifically concerns audiotape cassettes, its suggestions would be equally applicable to videotape cassetes.
Among suggestions in the Saito patent are "a lug aperture 78 in which a lug 79 is rockably mounted" as shown in FIG. 22; a cylindrical lug 99 having a hiatus 99d which, as shown in FIGS. 27 and 28 can be rotated to block or unblock a rectangular aperture; a cylindrical lug 104, an end of which has a blocking wall 104b, the position of which closes or opens the aperture 103 in FIG. 34; a lug 112 which is slidable to leave either one-half of an aperture 111 open as shown in FIG. 42; and a solid lug 114 shown in FIG. 44 which can be replaced by the tubular lug 115 shown in FIG. 45. Although the Saito patent does not explain the function of the tubular lug 115, its absence would permit a record-lockout finger to enter the aperture 113 into which those lugs interchangably fit.
While many of the Saito suggestions require a special opening, it would be desirable to employ a record tab that could be used in a cassette such as a VHS or Betamax cassette, either to close the opening left after breaking out a record-lockout tab or to close such an opening in a cassette which is identical except being molded without a record-lockout tab.